<?PHP // $Id: filter.php,v 1.2 2007/03/30 21:10:15 skodak Exp $
	  // This function looks for email addresses in Moodle text and 
	  // hides them using the Moodle obfuscate_text function. 
	  // Original code by Mike Churchward

function emailprotect_filter($courseid, $text) {

	
	if (!empty($CFG->formatstring)) {
		return $text;
	}
											
/// Do a quick check using stripos to avoid unnecessary work
	if (strpos($text, '@') === false) {
		return $text;
	}

/// There might be an email in here somewhere so continue ...
	$matches = array();

/// regular expression to define a standard email string.
	$emailregex = '((?:[\w\.\-])+\@(?:(?:[a-zA-Z\d\-])+\.)+(?:[a-zA-Z\d]{2,4}))';

/// pattern to find a mailto link with the linked text.
	$pattern = '|(<a\s+href\s*=\s*[\'"]?mailto:)'.$emailregex.'([\'"]?\s*>)'.'(.*)'.'(</a>)|iU';
	$text = preg_replace_callback($pattern, 'alter_mailto', $text);

/// pattern to find any other email address in the text.
	$pattern = '/(^|\s+|>)'.$emailregex.'($|\s+|\.\s+|\.$|<)/i';
	$text = preg_replace_callback($pattern, 'alter_email', $text);

	return $text;
}


function alter_email($matches) {
	return $matches[1].obfuscate_text($matches[2]).$matches[3];
}


function alter_mailto($matches) {
	return obfuscate_mailto($matches[2], $matches[4]);
}

?>
